Light fitting

ABSTRACT

A light fitting is adjustable to vary the beam direction and for this purpose comprises a rotatable support stem carrying a lamp housing to permit rotation of the lamp housing about a pivot axis inclined at 45° to the stem axis and to the central axis of the lamp housing. A handle fastened with the lamp housing and on the side of the stem remote therefrom can be manipulated to turn the lamp housing and stem around the stem axis to rotate the lamp housing about the pivot axis.

BACKGROUND OF THE INVENTION

This invention relates to light fittings, and is concerned in particularwith a light fitting having a support arrangement enabling the directionof the light beam emitted by the fitting to be adjusted.

Various support arrangements have been proposed in the past in which alamp housing enclosing the bulb holder can be rotated independentlyabout a first axis perpendicular to a central axis of the housing, andabout a second axis inclined at 45° to the first and central axes. Thisgeometrical arrangement allows the beam axis, which is along the centralaxis, to be adjusted to project in any direction to one side of a planeperpendicular to the first axis. Such light fittings are described forexample in our earlier patent specifications GB1581928 and GB1474186.Another know fitting is disclosed in specification FR2286343 andcomprises a housing journalled on a support stem for rotation about anaxis at 45° to the respective axes of the stem and housing. The stem isequipped with a radially projecting handle for rotating the stem, but torotate the housing about the 45° axis it must be grasped in the hand,which is a disadvantage because it will get hot due to the heat from thebulb. A further disadvantage is that continuous rotation about the 45 °axis is prevented by a stop, provided to prevent the electric wiresbecoming twisted, which can be electrically dangerous when adjusting thebeam direction.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided an electriclight fitting comprising a lamp housing enclosing a bulb holder andhaving a central axis, projection means extending from the housing alonga pivot axis inclined to said central axis, support means having arotation axis inclined to said pivot axis, the support means carryingmounting means thereon, said projection means being coupled to themounting means for rotation relative thereto about the pivot axis, andsaid projection means extending beyond the mounting means to provide ahandle for turning the housing about the pivot axis and for turning thehousing and support means about the support rotation axis. With a lightfitting embodying the invention a single handle located at a relativelyremote position from the bulb holder provides especially simple andconvenient adjustment of the housing and hence beam direction about thetwo adjustment axes, whereby such adjustment operations are greatlyfacilitated. The pivot axis preferably lies at 45° to the central andsupport axes, in which case the central axis can be adjusted through 90°from a position parallel to the support axis to a position perpendicularto the support axis by rotating the handle. If other ranges ofadjustment are required different angles of inclination may be selected.

In a preferred construction the mounting means is tubular and theprojecting means passes therethrough. In addition the support meanscomprises a contact adapted to rest against a contact located within theprojection means and having an annular surface extending around thepivot axis. This arrangement allows the housing to be made continuouslyrotatable about the pivot axis because wires which would become twistedcan be obviated.

BRIEF DESCRIPTION OF THE INVENTION

To assist a better understanding of the invention an exemplaryembodiment will now be described in more detail with reference beingmade to the accompanying drawings in which:

FIG. 1 is a schematic cross-sectional view of a light fitting embodyingthe invention; and

FIG. 2 is a more-detailed scrap section showing the connection betweenthe lamp housing and support stem.

DETAILED DESCRIPTION OF THE INVENTION

The light fitting illustrated in the drawing comprises a lamp housing 1having a cylindrical forward end portion and a conical rear end portionwith an apex angle of 90°. Mounted in the housing is a bulb holder 2positioned to support a low voltage bulb 3 on the central axis of thehousing for the fitting to project a beam of light centered on saidcentral axis. The housing is carried on a support stem 4 which is shownextending vertically downwards e.g. from an upper support structure (notshown). The stem comprises a tubular metal casing 5 on the axis of whichis located a central conductor 6. Fixed to the lower end of the casingis a cylindrical sleeve 8 having its axis inclined at 45° to the axis ofthe support stem. The end of the sleeve nearest the housing 1 has aninturned flange 9 and defines one contact for the supply of electriccurrent to the bulb holder, this contact being arranged to abut directlythe housing which is electrically conductive and connected electricallyby any convenient means to one terminal of the bulb holder. A secondcontact has the form of a pin 7 and is defined by an end portion of theconductor 6 projecting through an insulating spacer 10 supporting theconductor axially and in spaced relationship to the casing 5. Thecontact pin cooperates with a contact member 12 extending coaxiallythrough the sleeve 8 from within the housing 1. The inner end of themember 12 is connected electrically to the second terminal of the bulbholder, such as by means of a length of wire. An insulating sleeve 13surrounds the member 12 over the lengthwise portion extending throughthe opening in the housing conical wall and the adjacent end portion ofsleeve 8, an external shoulder on the insulating sleeve engaging theflange 9 and a retaining element 14 being fitted onto the inner end ofthe sleeve 13 within the housing 1 to secure it to the housing. From theforegoing it will be understood that the axis of member 12 is inclinedat 45° to the central axis of the lamp housing and to the axis of thesupport stem 4. The outer end of the member 12 is screw threaded andscrewed onto this end of the member is a handle 15 of insulatingmaterial, e.g. formed as a plastics moulding. The outer surface of thehandle is stepped so that it forms a smooth continuation of the outersurface of the mounting sleeve 8. It will be seen that the inner end ofthe handle helps to journal the member 12 within sleeve 8. Between thehandle 15 and the insulating sleeve 13, the member 12 has a flange 16with a conical surface defining an annular contact face against whichthe pin 7 rests and which at the position of contact with the pin liessubstantially perpendicular to the axis of the support stem.

The support stem preferably comprises a spring for pressing the pin 7into firm contact with the conical contact face of the flange 16. Inaddition, the support stem will be adapted, either by incorporationtherein of a rotating coupling or by suitable connection thereof to asupporting member, to permit rotation of the mounting sleeve 8 about thestem axis.

In one preferred construction the stem may incorporate a rotationcoupling of a form generally as shown in FIG. 6 of International PatentApplication PCT/GB89/00665 (Publication No. 89/12918) the contents ofwhich are incorporated herein by this reference. In such a case thetubular casing 5 may be integral with one part of the split housing ofthe coupling and the contact pin 7 may be constituted by thecorresponding pin contact of the coupling. With a stem of thisconstruction it will comprise an upper end part which may berotationally fixed, e.g. to a distribution track by means of anelectrical coupling as also described in the aforementionedInternational Patent Application No. PCT/GB89/00665, and a lower endpart which can be continuously rotated relative to the upper part.

Whatever arrangement is chosen to enable rotation about the stem axis,adjustment of the lamp housing about this axis may be achieved bymanipulation of the handle 15. Furthermore, by rotating the handle aboutthe pivot axis defined by sleeve 8, the inclination of the housing tothe stem axis is adjustable. Thus adjustment about both axes can beperformed simultaneously merely by holding the handle. In additionbecause the handle is remote from the bulb and of material having lowheat conductivity it will not get too hot to be held comfortably,whereby adjustment of the beam direction is further facilitated. Yetanother advantage is gained by enabling continuous rotation about bothaxes of adjustment since it is no longer possible to turn the housing inthe wrong direction to achieve the desired beam direction.

I claim:
 1. A light fitting comprising a lamp housing (1) having acentral axis, a bulb holder (2) mounted in the lamp housing forsupporting a light bulb having a predetermined beam direction, and asupport (4) having mounting means (8) coupled to the lamp housing toenable rotation of the lamp housing relative to the support about apivot axis inclined to said central axis, the support defining arotation axis inclined to the pivot axis, wherein the light fittingincludes means projecting from the lamp housing along the pivot axis andbeyond the mounting means to provide a handle (15) for turning the lamphousing about the pivot axis and about the rotation axis for adjustingthe beam direction.
 2. A light fitting according to claim 1, wherein thepivot axis is at an angle of substantially 45° to the central axis andto said rotation axis.
 3. A light fitting according to claim 1 whereinthe mounting means comprises a sleeve member (8), and said projectingmeans extends through the sleeve member and couples the lamp housing (1)to the support (4).
 4. A light fitting according to claim 1 wherein thelamp housing (1) is continuously rotatable about the pivot axis.
 5. Alight fitting according to claim 4, wherein the projecting meansincludes an electric contact (16) having an annular surface extendingabout the pivot axis, and the support (4) includes a contact element (7)resting against said annular surface
 6. A light fitting according toclaim 5, wherein the contact element (7) extends along the rotation axisand said annular surface (16) is substantially perpendicular to therotation axis at a surface of contact with said contact element.
 7. Alight fitting according to claim 5 wherein the contact surface isdefined on a contact member (12) extending from the lamp housing.
 8. Alight fitting according to claim 7, wherein the handle (15) is fastenedto the contact member (12).
 9. A light fitting according to any one ofclaims 1 to 8, wherein the handle (15) is of heat insulating material.10. A light fitting according to any one of claims 1 to 9, wherein thesupport includes a rotation coupling enabling continuous rotation of thelamp housing about said rotation axis.
 11. A light fitting according toany one of claims 1 to 10, wherein the mounting means (8) contacts saidlamp housing (1) around said pivot axis to provide an electricalconnection to the bulb holder.